[SOLVED]stallation fail

Hello,
the installation on my Joomla 3.8.2, php Version 5.6 failed with the following message, help appreciated, thank you!!

JInstaller: :Install: Die XML-Installationsdatei konnte nicht gefunden werden.
JInstaller: :Install: SQL-Fehler Table 'usr_web22252835_1.#__jem_events' doesn't exist
Erweiterung „Aktualisierung“: SQL Fehler beim Ausführen der Abfrage: „DB-Funktion mit Fehlercode 1146 fehlgeschlagen!
Table 'usr_web22252835_1.#__jem_events' doesn't exist
SQL =

ALTER TABLE `#__jem_events`
CHANGE `access` `access` INT(10) UNSIGNED NOT NULL DEFAULT '0',
ADD KEY `idx_venue` (`locid`),
ADD KEY `idx_access` (`access`),
ADD KEY `idx_checkout` (`checked_out`),
ADD KEY `idx_pubstate` (`published`),
ADD KEY `idx_createdby` (`created_by`),
ADD KEY `idx_language` (`language`)
;

“
Paket Installieren: Bei der Installation der Erweiterung trat ein Fehler auf: com_jem.zip

when you had jem installed before, you have to delete all jem db files, before a new installing!

there was no DB-entry with the JEM prefix, after failed installation there is an empty table "f7b_jem_config" which I deleted and tried again, same error. I forgot the first line of the error Message:
"JInstaller: :Install: Die XML-Installationsdatei konnte nicht gefunden werden."

If someone wants to try itself at the backend, I can send him login data via PM to a shadow copy of the page to play around...

Hi johnix,

there is some inconsistence: the installer thinks it's an update of an already installed JEM but the JEM tables are not there. Normally it's not required to uninstall JEM or manually remove DB tables before updating JEM.

For me it looks as if there is a "com_jem" entry in _extensions table causing the installer to execute some sql files required to update from version x to 2.2.2. But I'm surprised about the "#_events" - normally Joomla always replaces the "#" by site's table prefix. Also I've no idea why an xml file should be missing. :S

But ignoring these two question marks flying around my head you could try following: Please go to Extensions - Manage in backend and search for JEM. If it shows at least a line JEM - Administrator - Component mark this line and click Uninstall.
If not or it doesn't help we have to patch the DB a bit. Open the DB backend (e.g. phpMyAdmin) and enter table ..._extensions. There search for a "com_jem" entry - if you like by writing a SQL query like If such an entry exists delete it from table.

Another, last idea could be to locally extract the pkg_jem_v2.2.2.zip and install the zip files within "packages" folder one by one, starting with com_jem.zip.

Personally I tried on a fresh created site with J! 3.8.2 using PHP 5.6.32 - but got no problems, JEM package installed completely fine.

Unfortunately it's very late yet so I need to go offline (both, my PC and me )

Thank you!!
Problem was: Some entries in the DB, after deletion of all "com_jem" entries the installation succeeded.