LyX ⇒ Help me please (No counter subfig at save defined)

[kaleras45]

Hello,
I am writing my PhD thesis in Lyx 2.1.6 with document class spimufcphd and I would like to make figures side by side (Fig.1 a ……Fig.1 b).
When I tried to open a document (compiled fine there), it won't compile at all with a heap of errors:
The problem: Latex Error: No counter 'subfigure <at> save' defined

do you have an idea?
Cordially

[Johannes_B]

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